Artificial colorants for hair (for example, hair dyes) and methods for artificially coloring hair are well-known. Generally speaking, artificial colorants for hair function either by depositing colorants on the hair's exterior and/or by depositing colorants within the hair shaft. Removing such colorants from the exterior or interior of hair typically involves interfering with the hair/colorant interaction sufficiently to cause the colorant to dislodge from the hair.
U.S. Pat. No. 5,785,961 discloses mixing at the time of use-type methods and compositions for dyeing or bleaching hair. Specifically, the '961 patent discloses combining a first composition containing either a dye or a bleaching agent such as ammonia, an anionic surfactant and a higher fatty acid with a second composition containing an oxidizing agent such as hydrogen peroxide before use to form a composition to dye or bleach hair. However, the '961 patent does not disclose how to remove artificial colorants from hair. The '961 patent's dye compositions clearly do not remove artificial color from hair—instead, they provide artificial color to hair. The '961 patent's bleaching compositions also do not remove artificial color from hair. Rather, the bleaching agents in such compositions oxidize the melanin in hair by removing sulfur from it, thereby removing the natural hair color in an irreversible chemical reaction (oxidized melanin is substantially colorless).
Accordingly, the present invention addresses the need in the art for methods and compositions for removing artificial color from hair.